Trouble setting up Paul Minimotos

I'm beginning to suspect there is an issue with this particular set of brakes, but I wanted to check with you good folks first. I've set cantis and v-brakes since the 80s, so I have some experience setting them up. On my Zanc CX frame I am running the new Paul's Minimotos, and I am having trouble getting the pads to sit low enough to contact the rim. On three of four pads when Kool Stops are at the bottom of the slot (and I know you get better leverage with the pads mounted higher if you can, I just can't) they line up fine, albeit near the top of the brake track. On the fourth (front wheel of course) while using pliers to hold the pad down when I tighten the bolt I can just barely get the pad on the brake track, and I worry that it is going to rub on the tire. I've considered filing out the slot or filing down the top of the pad with a dremel, but I figured I'd check here for suggestions for a more adjustable brake pad.

I'm running the Koolstop Cross pads as the long MTB pads that came with the brake (with the added rubber to rake mud off the rims) just did not back off the rims far enough for practicle use, and hit the fork blades when made pulling the wheel hard. Mini-vs in general run pretty close tolerances, and that pad just barely worked with a perfectly true rim.

Anyway, I thought about the TRP Adjust M pads, but wondered if anyone had good luck with that setup. Are there any threaded pads that are more adjustable that the ball socket thingies on the Koolstops. If not, any other way to slope threaded pads down?

Thanks.

It may just be where Mike placed the posts on this frame, I run TRP 8.4 on my other cross bike and did not run into this problem. I know I could switch them to check, and I likely will, but the TRPs look a bit "modern for a lugged frame."

Re: Trouble setting up Paul Minimotos

Have you tried swapping the spherical washers on the pad post. The Pauls I've used are delivered with the thick washer on the pad side, thin on the outside. Moving the thin washer to the inside will allow the brake arm to rotate further and, thus, lower. It won't make a huge difference, but may be enough.

Canti post placement, both height from axle and width, brake design and pad stack all play a part. No standards exist so it is often hit and miss. Of the four canti bikes I've had only one had no problems with any brake I tried. Wide post placement is the most forgiving and Pauls specifically don't like narrow post spacing. If your posts are under 80mm apart you'll have issues with Pauls unless the height from the axle is perfect.

Re: Trouble setting up Paul Minimotos

You may be right but you can't swap the washers on these pads because they get too close to the brake. You'll see there is a lip on the brake itself that comes in contract with the brake pad carrier if you use the short spacer. Again, it could be filed off, but I'd rather not do surgery on these if I eventually need to sell them off. I'd rather round of the top of the brake pads themselves, because as they wear down, they move down on the brake surface (right?).

Re: Trouble setting up Paul Minimotos

Curious. I'm not specifically familiar with the Cross pads, but it sounds like your posts are very close together, like 77-79mm, or too high (not likely). I had one cross bike with 79mm wide posts and I couldn't get Pauls to fit with any pads I tried. I agree you shouldn't do surgery on the brakes themselves. I'd measure the post spacing and try the TRP's for comparison. What did you run on this bike previously, if anything ?

Re: Trouble setting up Paul Minimotos

Ah, interesting point, I am running 23mm rims on the frame, and really like them, but that may be the issue. I'll measure the distance between the posts, I assume this is a center to center measurement?

I replaced a pair of TRP EuroX cantis which were just shrieking and shuddering something awful, and not stopping as quickly as I'd like.

Maybe I can dremel out the back of the brake pad holder where that lip is so I can use the thinner spacer? Or this may be the time to build up some Stanz ZTR Alpha 400 rims (narrower and tubeless) to the DT 240s laying around in the basement.

These are the ones I'm using now, and they stop very well on these brakes. I'm just having trouble with the adjustment.

Re: Trouble setting up Paul Minimotos

80mm c to c is what most are using these days
the paul comp stuff seems ultra picky about this, i have a set of minimotos in a box that i can't use. i even dremeled out the vertical spacing to try and win some more adjustment. no joy. my rims were 19mm, but my spacing was also closer to 72mm. if you're closer to 80 you may be able to pull it off with some creativity

Re: Trouble setting up Paul Minimotos

These are the ones I'm using now, and they stop very well on these brakes.

Well, turns out those pads were the ones I was going to use on my "soon to purchase" Mini Motos.

Originally Posted by prolix21

paul comp stuff seems ultra picky

After these experiences I think I'll borrow a set of Neo Retros to make sure "Pauls" fit my bike before spending a small fortune, assuming all Paul cantilever post brakes "fit" the same. This is concerning because the same "borrowed" Neo Retros didn't fit another frame of mine with 79mm spacing. Posts were a bit low, but geez, this appears to be a common issue.

Re: Trouble setting up Paul Minimotos

These brakes are amazing but very sensitive to position and stud spacing. We set up 4 cx bikes with these brakes today without issue (hot tubes, Santa cruz and two of my own). But all were 80mm stud spacing and used a standard 20(+/-)mm width rim. If these are requiring 80mm stud width for a 20mm rim you'll want to add at least the additional mm of rim width to have them function the same. Something to consider before purchase or mention to your builder before hand. Always pays to have parts in hand for a build. I'm glad this came up as I'll be doing a wide rim minimoto combo soon and it looks like switching to a 280x85 (or there abouts) stud position may be the ticket to uber-stopping.

Re: Trouble setting up Paul Minimotos

Glad I found this thread - sounds like I better measure before laying out the cash. I switched tithe cheap 86mm Tektros to see how I get along with v-brakes on the CX bike. As it turns out, we get along quite well!

@donevwil - let me know if you want to try out some Neo Retros, mine are currently collecting dust.

Re: Trouble setting up Paul Minimotos

This thread may be a bit misleading- the MiniMoto will work fine (great actually) if everything is to standard spec. Once you get a wide rim or narrow stud spacing that's when problems pop up.

Originally Posted by Oregonic

Glad I found this thread - sounds like I better measure before laying out the cash. I switched tithe cheap 86mm Tektros to see how I get along with v-brakes on the CX bike. As it turns out, we get along quite well!

@donevwil - let me know if you want to try out some Neo Retros, mine are currently collecting dust.

Re: Trouble setting up Paul Minimotos

Slight thread shift:

I'm trying to set up some minimotos. Front posts are 80mm c-c rear is ~ 75mm c-c.
I'm pairing them up with Ultegra SL levers.

How much space should I be aiming for between brake pad and rim? Right now, I have mine set up with ~ 2mm of space but when I squeeze the lever I'm only getting engagement when the lever gets to about 3/4" away from the drops.

It seems like this isn't enough space between pad/rim.
But its been over 10 years since I've ridden in any sort've muddy condition and about the same amount of time since I last set up a pair of v or cantilever brakes.

Re: Trouble setting up Paul Minimotos

Originally Posted by Rosko

... Once you get a wide rim or narrow stud spacing that's when problems pop up.

Wide rims, narrow stud spacing, or swapping out the Thinline pads. The stock Thinline pads with their long tails don't fit many forks. Granted you can cut them off, but most (i.e. the OP) find a shorter, slicker road/cx pad set-up to swap. These usually have a larger stack height.

All Paul brakes are great, but it is certainly wise to measure or borrow/mock-up a set before plunking down $250+.